Create Extent for Label (Point Feature)

[Wunder0]

Hello,

I wanted to ask, if there is a way to create a extent for labels (e.g. for everything that is in "place" layer).

Background: When using MapboxVectorLayer (usually used for MapBox..) in OpenLayer to use client side rendering no Labels are shown. After a bit of debugging I found out that the root cause is the missing extent box of the labels. Therefore when declutter is executed all labels are removed. Currently, the only way seems to use no decluttering at all, what overflows the map at some zoom levels.

Does anyone have an better idea?
(I already planed to switch to MapLibre in my implementation, but there is still a lot to do)

[pnorman]

What do you mean by extent? In vector tiles the term extent is the number of integer coordinates in each layer's drawing space. There is a bounds in tilejson, but that is for the entire tileset, not for layers within it.

[Wunder0]

Hello @pnorman,
sorry for beeing imprecise. I think I wanted to know if it is possible to add a geometry to a symbol (point feature of "place" layer), e.g. by converting it to a polygon (e.g. where the label sits in the center)? This should result in having a bounding box for the labels (e.g. size of box depending on which layer the label shall be rendered: Country has much bigger bounding boxes than small cities).

I noticed while debugging OpenLayers that on their example https://openlayers.org/en/latest/examples/mapbox-vector-layer.html, the city names are rendered. When checking the features in the ol.render.canvas.TextBuilder.js I noticed that the feature coming from mapbox having extents (so a real geometry rather than a point):
{ "id_": 424317935, "type_": "Point", "flatCoordinates_": [ -10899308.737239853, 4774562.534805249 ], "flatInteriorPoints_": null, "flatMidpoints_": null, "ends_": [ 2 ], "properties_": { "code": "US", "name": "United States", "scalerank": 1, "type": "country", "mvt:layer": "country_label" }, "stride_": 2, "extent_": [ -10899308.737239853, 4774562.534805249, -10899308.737239853, 4774562.534805249 ] }
while when using my own vector layers, hosted with tileserver-gl-light the extent is undefined, because the feature has no geometry. As a result, the declutter function of OpenLayers removes all my labels from the map.

Best regards,
Andreas